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含水率影响下尾矿砂内摩擦角随标贯击数变化研究 总被引:1,自引:0,他引:1
尾矿砂样品在运输和存放过程中均存在易扰动的特点,但考虑到工程造价以及人力资源等因素,目前在大部分上游式尾矿坝的工程地质勘察中难以建立现场试验室,所得抗剪强度指标与实际情况存在一定误差。针对这种现状,结合某铅锌矿尾矿坝现场试验结果,从现场简易试验获得的含水率和标准贯入击数进行分析,并对基于含水率影响下尾矿砂内摩擦角随标准贯入击数变化规律进行了研究,提出了考虑上覆压力作用下标准贯入击数的修正公式,并推出了用标准贯入击数估算尾矿砂内摩擦角的方法。通过几个实例验证:除当修正后的标准贯入击数N1>8(5%< <20%)情况下以外,该方法均能够有效地估算尾矿砂内摩擦角。研究结果表明,该方法在以后的上游式尾矿堆积坝的工程地质勘察工作中具有较强的应用价值。 相似文献
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为了在国内岩土设计中很好利用英国标准(BS)标贯设备的试验结果,对英国标准和中国标准(GB)标贯设备及试验结果进行分析,研究相关性。BS和GB标贯设备主要的区别是前者的锤垫质量大于后者,造成试验时两者锤击能量有差别,因此,获得的标贯击数不同。通过采用标贯能量分析仪,测量配置不同直径钻杆的BS和GB设备试验时的实际锤击能量,计算两者不同的实际锤击能量与理论锤击能量的能量比,利用能量比的差别分析BS与GB标贯击数的相关性,建立相关公式。分析显示,试验时BS标贯设备比GB标贯设备的锤击传递能量要小,标贯击数要大;钻杆直径为50 mm比直径为42 mm传递的锤击能量略高,标贯击数略低。通过研究,最终建立了BS与GB标贯设备试验结果的相关关系,英标标贯设备获得的数据从而能更好运用于中国标准中,并提供符合中国利用标贯评价的岩土设计参数。 相似文献
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标准贯入试验是现场测定土体工程性质的重要原位试验,是现场快速判定土体密实度的重要依据,具有及时、可靠、经济等特点,在地质勘察中被广泛的应用。本文通过介绍标准贯入试验的基本原理和设备,比较了英国规范、美国ASTM规范和我国岩土工程勘察规范之间标准贯入试验的差异,介绍了标准贯入试验所适用的经验公式,结合在美国ASTM规范指导下具体的工程实践结果,应用标准贯入试验的结果分析了苏丹国尼罗河Dagash流域内的土体工程性质,对比钻探所得土样和袖珍贯入测力计试验结果,验证了标贯结果的正确性。 相似文献
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标准贯人(“标贯”)试验锤击数,要确定粘性土地基承载力标准值简易计算公式。将经杆长修正的标准贯人击数N进行统计分析,再把修正击数平均值带人相关方程,计算粘性土的承载力标准值fk,从而简化了计算过程。 相似文献
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黄土由于特殊的结构性导致其水敏性,以往相关研究多采用室内试验的方法。文章以动三轴弯曲元试验系统对原状黄土和饱和黄土在各级围压下的剪切波速与轴向变形进行了测试,并对兰州市西固区某饱和黄土场地进行了现场钻孔及原位试验。室内及现场试验结果表明,黄土遇水模量软化,饱和黄土更具有触变性。进一步对比饱和粉土与砂土的剪切波速与标贯击数统计关系,发现饱和粉土由于触变性导致标贯击数较小,而剪切波速为小应变无损测试,最终表现为剪切波速相同的饱和粉土与砂土,粉土标贯击数显著小于砂土。 相似文献
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以变形作为地震工程安全设计的控制标准是近年来逐渐发展的趋势,海港公路工程中大型重力式沉箱码头在液化地基中的地震残余变形的分析是较复杂的。采用定义在应变空间中考虑土体动主应力轴方向偏转影响的多重剪切机构塑性模型的动力有效应力分析方法,分别从地震加速度幅值、码头底部置换砂与码头身后回填砂土的标贯击数、处理范围以及码头宽高比等详细分析了码头地震残余变形随各影响因素的变化规律,结果表明,地震动水平、置换砂处理厚度、标贯击数和码头的宽高比是较敏感的影响因素,对残余变形具有显著的影响,且回填砂的加固存在一个合理有效范围。计算绘出的一系列分布图有助于工程设计者初步预测码头的地震残余变形 相似文献
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对南昌赣江(南支)与抚河(故道)入湖尾闾河道之间的湖积冲积平原区域内采用冲击钻进和回转钻进所做的SPT击数进行对比分析,得出两类钻探工艺的击数差异;并采用对砂层扰动较轻的静力触探试验(CPT)作为标准贯入试验(SPT)的对比试验,用以检验两种钻探工艺的SPT击数所反映的砂土密实度与真实密实度的差异,同时得到三点认识:(1)在饱和砂层中采用冲击钻进做SPT,对砂层的扰动很大,建议采用回转钻进进行SPT;(2)冲击钻进对粗颗粒砂土的扰动程度大于细颗粒砂土;(3)冲击钻进对浅部砂土的扰动影响较大,随着埋深增大,冲击造成的扰动影响越来越小。最终建立两种钻探工艺不同深度段各砂土的SPT击数经验关系式。 相似文献
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通过对铁路工程地质勘察钻孔质量评价因素的多层次、多因素研究,建立铁路勘察钻孔质量综合评判指标体系层次模型,运用层次分析法确定每个影响因素的权重,并采用模糊数学基本原理对铁路钻孔质量进行综合评判。在评判模型中,综合考虑影响铁路工程钻探质量的定量、非定量指标,以其成孔条件、钻探记录、原位测试为基本准则层,根据实际现场判断手段确立每个准则下的指标层,将指标层针对评判分级标准转换成隶属度矩阵,利用模糊数学原理综合评判铁路钻孔钻探质量等级。 相似文献
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土工格栅在青藏铁路多年冻土区路基工程中的应用 总被引:3,自引:0,他引:3
以青藏铁路多年冻土区清水河冻土加筋路堤试验段为例,对土工格栅在铁路路基工程中的应用原理及设计思路进行了叙述.通过对路基裂缝进行调查、分析和比较,土工格栅对加强路基整体稳的作用是肯定的.在多年冻土区路堤中,使用土工格栅加筋层对防止路堤纵向裂缝的产生、抑制横向寒冻裂缝具有明显的作用. 相似文献
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A. Kayabasi 《Environmental Earth Sciences》2012,66(8):2171-2183
The Standard Penetration Test (SPT) is one of the most frequently applied tests during the geotechnical investigation of soils. Due to its usefulness, the development of empirical equations to predict mechanical and compressibility of soil parameters from the SPT blow count has been an attractive subject for geotechnical engineers and engineering geologists. The purpose of this study is to perform regression analyses between the SPT blow counts and the pressuremeter test parameters obtained from a geotechnical investigation performed in a Mersin (Turkey) city sewerage project. In accordance with this purpose, new empirical equations between pressuremeter modulus (E M) and corrected SPT blow counts (N 60) and between limit pressure (P L) and corrected SPT blow counts (N 60) are developed in the study. When developing the empirical equations, in addition to the SPT blow counts, the role of moisture content and the plasticity index of soils on the pressuremeter parameters are also assessed. A series of simple and nonlinear multiple regression analyses are performed. As a result of the analyses, several empirical equations are developed. It is shown that the empirical equations between N 60 and E M, and N 60 and P L developed in this study are statistically acceptable. An assessment of the prediction performances of some existing empirical equations, depending on the new data, is also performed in the study. However, the prediction equations proposed in this study and the previous studies are developed using a limited number of data. For this reason, a cross-check should be applied before using these empirical equations for design purposes. 相似文献
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滑坡灾害防治工程中应注意的几个问题 总被引:1,自引:0,他引:1
滑坡灾害防治工程成败的关键问题 ,取决于滑坡勘查、设计以及施工质量。为提高滑坡防治工程水平 ,更好地为公路、铁路、市政建设服务 ,本文从滑坡勘查、治理设计、治理施工出发 ,探讨滑坡防治工程中应注意的几个问题。 相似文献
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Shear wave velocity is one of the most important input parameter in the analysis of geotechnical earthquake engineering problems,
particularly to estimate site-specific amplification factor and ground response study. Dynamic in situ tests such as spectral
analysis of surface waves (SASW) or multichannel analysis of surface waves (MASW) are very expensive. Also due to lack of
specialized personnel, these tests are generally avoided in many soil investigation programs. Worldwide, several researchers
have developed correlations between the SPT ‘N’ value and shear wave velocity ‘V
s’, which are useful for determining the dynamic soil properties. In the present study, more than 400 numbers of soil borehole
data were collected from various geotechnical investigation agencies, government engineering institutes and geotechnical laboratories
from different parts of Mumbai city, which is financial capital of India with highest population density. In this paper, an
attempt has been made to develop the correlation between the SPT ‘N’ value and shear wave velocity ‘V
s’ for various soil profile of Mumbai city and compared with other existing correlations for different cities in India. Using
Geographical Information System (GIS), a geospatial contour map of shear wave velocity profile for Mumbai city is prepared
with contour intervals of 25 and 50 m/s. The scarcity of database or maps of shear wave velocity profile for Mumbai city will
make the present geospatial contour maps extremely useful and beneficial to the designer, practitioners for seismic hazard
study involved in geotechnical earthquake engineering. 相似文献
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Visualization of geotechnical data by means of geographic information system: a case study in Eskisehir city (NW Turkey) 总被引:2,自引:2,他引:0
Recently, geographic information system Software’s are widely used in engineering geology applications. Such a study was performed
in the Eskisehir urban area of about 30 km2 via geo-engineering maps, cross-sections and panel-block diagrams, which are formed to predict the properties of foundation
soil. In order to determine the engineering geology properties of the region, physical and mechanical characteristics of the
soil profile were tested on 1,011 disturbed and 383 undisturbed samples from a total of 170 boreholes. Topographic, lithological
and geotechnical data of the region were compiled as a database in computer. Five geological cross-sections were drawn to
decipher specifically the alluvial deposits in detail in densely populated areas. Hence, geological characteristics of the
area were evaluated in a three-dimensional mode. Five standard penetration test (SPT) cross-sections at the same directions
and SPT, uniaxial compressive strength (qu) and soil class Zonation maps were produced at different depths and panel-block
diagrams were also created to define the geo-engineering properties of the investigation area. In this respect, the sub-surface
of the study area is fully visualized and useful predictor maps, cross-sections and panel-block diagrams are performed to
be used in further studies. 相似文献
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藏东南的喜马拉雅东构造结地区作为青藏高原隆升最快的地区之一,复杂的地质背景条件决定了该区工程地质问题的复杂性和特殊性,并孕育了多种地质灾害。文章通过遥感解译、无人机测绘以及野外现场调查,详细分析了喜马拉雅东构造结北西侧通麦至鲁朗段已有滑坡的发育特征,总结了地质构造对滑坡的控制作用,结果表明:(1)构造演化形成的高陡斜坡为滑坡形成提供地形条件,滑坡后缘的断裂破碎带,为雨水入渗提供通道,形成滑坡边界;(2)斜坡岩体中发育的贯通性构造节理为滑坡提供滑动条件和物质基础;(3)地震震动对岩体结构造成直接破坏,并诱发同震滑坡。多种构造作用的耦合造成了川藏铁路通麦至鲁朗段滑坡的高易发性,相关结果可为铁路修建过程的边坡灾害管控提供参考和支撑。 相似文献
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基于GIS的铁路工程地质信息系统的构建 总被引:12,自引:0,他引:12
主要对构建铁路工程地质信息系统的必要性,GIS在铁路系统中的应用现状,铁路工程地质信息系统涉及的基本内容,以及如何构建基于GIS的铁路工程地质信息系统等作了详细的论述,并给出了一些对铁路工程地质信息系统构建有益的建议。 相似文献